teaching of part of forest protection lessons (abiotic, biotic factors, bark beetles, bark beetle control in Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague (2011 – present)

Natural disturbances such as windthrow and bark beetle Ips typographus L. outbreak often affect protected areas with non-intervention type of management located in close proximity to managed forest stands. This raises concerns about the migration of the beetle outbreak from non-intervention zones to adjacent managed forests. In this study we analyzed the spatiotemporal dynamics of large-scale disturbances by intervention and non-intervention type of management in the Tatra mountains (Central Europe). We collected a time series of Landsat images from 2003 to 2014, and applied maximum likelihood classification to map the extent of forest, windthrow, clear-cuts, beetle outbreak and fire. Our classified maps achieved high overall accuracies: 0.93 ± 0.03 ≤ OA ≤ 0.96 ± 0.03. The extent of forest declined over the study period. We found higher rate of beetle induced tree mortality in non-intervention versus intervention zone. Within two growing seasons after the windthrow, beetle infestation occurred in close proximity to uncleared windthrow (< ~ 250 m), which suggest the positive effect of salvage logging (removal of windthrown trees) on lowering the risk of beetle outbreak. The two times higher sum of disturbances in intervention then in non-intervention zone indicated the limited impact of sanitation felling (removal of standing beetle infested trees) to reduce beetle population. However, sanitation felling highly contributed to the decline of the forest cover. Overall, our results document the dynamics of windthrow, bark beetle and clear-cuts by type of management, and limited impact of logging activities in reducing beetle outbreak in neighboring areas with intervention and non-intervention type of management.

Norway spruce forests (Picea abies Karst.) of the Carpathian High Tatra Mountains have been subject to unprecedented tree mortality caused by attacks of the Eurasian spruce bark beetle (Ips typographus L.) in recent decades. The outbreaks were preceded and accompanied by wind throw events and periods of increased seasonal temperature. We obtained climatic data and data on tree mortality due to storm throw and bark beetles by using a combination of direct dead tree inventory and remote sensing techniques, and examined annual tree loss change over a 26-year period in a forest district of the Slovak High Tatra National Park. In particular, we found that the combination of the previous year's maximum daily temperature sum, tree mortality caused by wind, and bark beetle-caused tree mortality best explained the annual tree loss change in nonlinear regression models. The number of trees infested by bark beetles clearly increased with maximum air temperature sums ranging from 2850 to 3150 ° days, but declined below or above this thermal optimum. Annual tree mortality clearly increased subsequent to years associated with seasonal temperature sums allowing for the development of sister broods. Given consistently favourable future climatic conditions for development of I. typographus populations in the study area, a possible shift from the now predominantly uni-voltine to multi-voltine bark beetle populations might increase attack pressure also at high elevation sites.

@article{Havašová2015,
title = {Applicability of a vegetation indices-based method to map bark beetle outbreaks in the High Tatra Mountains},
author = {M. Havašová and T. Bucha and J. Ferenčík and R. Jakuš},
url = {http://afrjournal.org/index.php/afr/article/viewFile/388/466},
year = {2015},
date = {2015-05-18},
journal = {Annals of Forest Research},
volume = {58},
number = {2},
pages = {295-310},
abstract = {Automatic identification of forest patches disturbed by the spruce
bark beetle Ips typographus L. is crucial to reveal the rules of following
bark beetle outbreaks on the landscape scale. Landsat imagery provides
free resources to outline past and present gradations of bark beetle outbreaks
(BBOs). The objective of this study is to identify the most sensitive
vegetation index through different method of vegetation index differencing
to identify past and actual bark beetle outbreaks. Six Landsat Thematic
Mapper (TM) images, from 2005–2009 and 2011, were converted into selected
vegetation indices (VIs) sensitive to conifer tree health in a Norway
spruce–dominated forest in the High Tatra Mountains. The Vegetation Condition
Index (VCI), Moisture Stress Index (MSI), Normalised Difference
Moisture Index (NDMI), Normalised Difference Vegetation Index (NDVI),
Disturbance Index (DI) and Changed Disturbance Index (DI´) were calculated
separately for every year, and the methodology of vegetation index
differencing was applied to multiple two-year time periods (2005–2006,
2006–2007, 2007–2008, 2008–2009 and 2010–2011), thus producing the
Changed Vegetation Index (ΔVI). A set of thresholds was established on
ΔVI to classify disturbed and undisturbed forest due to BBOs; the sensitivity
of different VIs to identify BBO was equally evaluated. The highest
accuracies of classifications were reached in 2007 and 2011 (kappa index
of agreement >70% and >40%, respectively), which were characterised
by an epidemic phase of a BBO. All selected VIs were highly sensitive to
BBOs, except for NDVI. The stable threshold value for change detection
is not widely applicable to detect past forest disturbances caused by bark
beetles, however. Finally, for further research of the epidemic phases of
BBOs, we recommend the utilisation of the vegetation indices VCI, MSI and
NDMI to detect BBOs because of their simplicity and easy interpretability},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Automatic identification of forest patches disturbed by the spruce
bark beetle Ips typographus L. is crucial to reveal the rules of following
bark beetle outbreaks on the landscape scale. Landsat imagery provides
free resources to outline past and present gradations of bark beetle outbreaks
(BBOs). The objective of this study is to identify the most sensitive
vegetation index through different method of vegetation index differencing
to identify past and actual bark beetle outbreaks. Six Landsat Thematic
Mapper (TM) images, from 2005–2009 and 2011, were converted into selected
vegetation indices (VIs) sensitive to conifer tree health in a Norway
spruce–dominated forest in the High Tatra Mountains. The Vegetation Condition
Index (VCI), Moisture Stress Index (MSI), Normalised Difference
Moisture Index (NDMI), Normalised Difference Vegetation Index (NDVI),
Disturbance Index (DI) and Changed Disturbance Index (DI´) were calculated
separately for every year, and the methodology of vegetation index
differencing was applied to multiple two-year time periods (2005–2006,
2006–2007, 2007–2008, 2008–2009 and 2010–2011), thus producing the
Changed Vegetation Index (ΔVI). A set of thresholds was established on
ΔVI to classify disturbed and undisturbed forest due to BBOs; the sensitivity
of different VIs to identify BBO was equally evaluated. The highest
accuracies of classifications were reached in 2007 and 2011 (kappa index
of agreement >70% and >40%, respectively), which were characterised
by an epidemic phase of a BBO. All selected VIs were highly sensitive to
BBOs, except for NDVI. The stable threshold value for change detection
is not widely applicable to detect past forest disturbances caused by bark
beetles, however. Finally, for further research of the epidemic phases of
BBOs, we recommend the utilisation of the vegetation indices VCI, MSI and
NDMI to detect BBOs because of their simplicity and easy interpretability

@article{Mezei2012,
title = {The relationship between potential solar radiation and spruce bark beetle catches in pheromone traps},
author = {P. Mezei and R. Jakuš and M. Blaženec and S. Belánová and J. Šmídt},
issn = {18448135},
year = {2012},
date = {2012-01-01},
journal = {Annals of Forest Research},
volume = {55},
number = {2},
pages = {243-252},
abstract = {We analysed the relationship between the amount of potential solar radiation and spruce bark beetle Ips typographus(L.) catches in pheromone traps in an unmanaged nature reserve in the Carpathians (middle Slovakia region), from 2006 through 2009. This relationship was analysed under outbreak conditions. The number of traps varied in different years from 70 to 92. The traps were installed in spruce-forest-dominated stands affected by a windstorm in 2004. A GPS device was used to mark the position of the pheromone traps. The potential solar radiation was calculated with GIS tools for three different time periods in each year: with entire year, for main flight season of the spruce bark beetle and the spring swarming period. The relationship between the amount of potential solar radiation and the spruce bark beetle catches was statistically significant for each year and each time period except for the spring swarming in 2007, when the pheromone traps were not set up on time.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

We analysed the relationship between the amount of potential solar radiation and spruce bark beetle Ips typographus(L.) catches in pheromone traps in an unmanaged nature reserve in the Carpathians (middle Slovakia region), from 2006 through 2009. This relationship was analysed under outbreak conditions. The number of traps varied in different years from 70 to 92. The traps were installed in spruce-forest-dominated stands affected by a windstorm in 2004. A GPS device was used to mark the position of the pheromone traps. The potential solar radiation was calculated with GIS tools for three different time periods in each year: with entire year, for main flight season of the spruce bark beetle and the spring swarming period. The relationship between the amount of potential solar radiation and the spruce bark beetle catches was statistically significant for each year and each time period except for the spring swarming in 2007, when the pheromone traps were not set up on time.

@article{Mezei2011,
title = {Population dynamics of spruce bark beetle in a nature reserve in relation to stand edges conditions},
author = {P. Mezei and R. Jakuš and M. Blaženec and S. Belánová and J. Šmídt},
issn = {13365266},
year = {2011},
date = {2011-01-01},
journal = {Folia Oecologica},
volume = {38},
number = {1},
pages = {73-79},
abstract = {Over the period 2006–2009 spruce bark beetle (Ips typographus [L.]) population was monitored
after two windstorm events in a nature reserve in Slovak Ore Mountains. The monitoring was carried out with pheromone traps in three different forest edges: 1) edge of wind-felled trees area, 2)
disturbed stand edge and 3) undisturbed stand edge. The one-way ANOVAconfirmed statistically
significant differences among stand edges in each year and a post-hoc test was applied. In first
two years after the primary disturbance the most attractive for spruce bark beetle was the edge of
wind-felled trees area. After two years from the primary disturbance the most attractive became
the disturbed stand edge. The undisturbed stand edge showed a similar attractivity for spruce bark
beetles almost over the whole monitoring period.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Over the period 2006–2009 spruce bark beetle (Ips typographus [L.]) population was monitored
after two windstorm events in a nature reserve in Slovak Ore Mountains. The monitoring was carried out with pheromone traps in three different forest edges: 1) edge of wind-felled trees area, 2)
disturbed stand edge and 3) undisturbed stand edge. The one-way ANOVAconfirmed statistically
significant differences among stand edges in each year and a post-hoc test was applied. In first
two years after the primary disturbance the most attractive for spruce bark beetle was the edge of
wind-felled trees area. After two years from the primary disturbance the most attractive became
the disturbed stand edge. The undisturbed stand edge showed a similar attractivity for spruce bark
beetles almost over the whole monitoring period.